Intraband relaxation via polaron decay in InAs self-assembled quantum dots

• Published in: Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2004-10, Vol.70 (16), p.161305.1-161305.4, Article 161305
• Main Authors: ZIBIK, E. A, WILSON, L. R, STEER, M. J, HOPKINSON, M, GREEN, R. P, BASTARD, G, FERREIRA, R, PHILLIPS, P. J, CARDER, D. A, WELLS, J-P. R, COCKBUM, J. W, SKOLNICK, M. S
• Format: Article
• Language: English
• Subjects: Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Materials Science; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Quantum dots
• ISSN: 1098-0121; 1550-235X
• DOI: 10.1103/physrevb.70.161305

Three distinct channels for the decay of polarons in InAs quantum dots are identified using energy and temperature-dependent far-infrared pump-probe spectroscopy. For energies up to ~53 meV a monotonic increase of the polaron relaxation time is observed, the polaron decay being shown to occur into two longitudinal acoustic phonons. Above this energy additional decay channels into two optical phonons are allowed, leading to the observed reduction of the decay time. We also demonstrate interlevel polaron transfer between the closely spaced p-like excited states, with measured transfer times in good agreement with calculations for an acoustic-phonon-mediated process.